Fuel Problems (?) Everything has been replaced
 

Hi there! My husband has a 1986 Audi Coupe Gt that is having stuttering/power loss problems. He had has replaced: Fuel Pump, Spark Plugs, Water Pump, Timing Belt, Fuel Tank, Fuel Accumulator (Sp?), lines, filter, checked vacume hoses and it's still doing the same thing! When turned on the car will idle perfectly, but once driving has no power under load. Either way it won't rev over 3,000 RPM's. Manual Transmission. He loves this car, but hasn't really been able to enjoy it. Please help! What are we missing?